Whilst your reversing camera system really only needs the camera that you attach to the rear of the vehicle/trailer & the monitor for viewing there is of course a bit more to it than that. Here's a run-down on features and options and tips for putting the ideal system together to meet all your rear view and reversing needs.
Electrochromatic Rear View MirrorAn electrochromatic rear view mirror replaces your vehicle's normal rearvision mirror. It features a second screen that displays vision from the reversing camera. When activated, the mirror features a small colour LCD screen in a portion of the mirror space (typical size 50mm x 38 mm) with images provided by the Reversing Camera keeping you aware of any obstacles at the rear of the car. When not in use, the LCD screen is invisible to the eye and the entire area of the Electrochromatic Mirror works as a mirror. The Electrochromatic mirror can be wired up so that it comes on automatically anytime the vehicle is put into reverse gear, and you can often also install a manual switch.
Everybody wants the best quality they can get for the cheapest outlay right? The gap
in quality between the types of image sensors used in the different types of cameras has been narrowing as technology develops. In terms of vehicle rear view cameras, the best value for money is with the CMD cameras. These now have the better image quality than the old-version CMOS cameras and are much cheaper than CCD cameras (CMD is now very close in picture quality to CCD). The cameras made by VMS that we have selected to stock in the ExplorOz Shop
use CMD image sensors.
Another factor to look at is night vision. If night vision is important to you, you might like to specifically look for a camera that comes with infrared illuminators. Typically, the illuminators should provide a minimum of 3-6 metres of illumination, or you can get 6-9 metres with a higher-end infrared camera.
If you're considering a wireless system, consider the implications of video interferance if you wish to use the unit whilst driving forward as a rear-vision system.
Some reversing kits are now available with built-in audio intercoms, which allows the driver to more easily communicate with a spotter outside the vehicle. If you're building your own kit, you could add the audio into your system by installing a camera that includes a (waterproof) microphone.
A wide angle of viewing means you're more likely to spot
obstructions in the monitor, particularly those that are very close and would normally be in your "black spot". But wider is not always better. In fact, going too wide produces a "fish-eye" image that will be extremely distored and very dangerous to use as part of a rear view or reversing camera system.
The field of view provided by the camera is determined by a combination of image sensor size & lens focal length. The larger the image sensor, the wider the possible field of view. However, a larger image sensor does not necessarily guarantee a wider field of view. Many rear view camera systems utilize a 1/4" image sensor, and provide only a 60 to 90 degree field of view. While a 90 degree field of view may be sufficient for some smaller vehicles, a 120 degree field of view is strongly preferred. You should absolutely avoid any system that produces lower than a 90 degree field of view. Most high quality rear view cameras that utilize a 1/3" image sensor produce a 120 degree field of view that is ideal for most applications.
Now, remember our first question at the top of the article? What are you going to use the camera for? This is where you need to think about the angle of the camera you select. Reverising and rear view is not the same. If you want to use the camera for rear-vision distance viewing instead of your big wide mirrors on the side of your vehicle in order to see behind your caravan, then opt for a camera with an angle of around the 90-95 degrees mark. Mount this one on the back of your van.
The ideal scenario is a two-camera system with a toggle switch on your dash to select the appropriate camera for your situation. For example, you could also have a wide-angle (150 - 170 degree) camera on the rear of your caravan, or mount this on the rear of your tow vehicle or have all 3 cameras!
Type of Camera/Camera Mount
There are four common types of cameras used for rear view/reversing camera systems, but for 4WDs, camper trailers, caravans, motorhomes the type best suited to the job is the surface mount camera. These cameras are usually mounted high on the rear of a vehicle, aimed down at approximately 45 degrees. This mounting position provides a view of the area behind the vehicle, and because of the downward angle, provides excellent depth perception.
The other three types of camera are the keyhole or "flush" mount (which you install by drilling into the rear bumper), the license mount (which are wide & long designed to be installed straight into the license plate screws), and the side mount. Side mounts types are a bit like the surface mount and are often in a swivel hub mount or are set on an angle in a housing.